1. Field of the Invention
The present invention relates to a soil compacting device and to a method for operating a soil compacting device. The present invention can be used for working machines for soil compaction, such as tampers or vibrating plates.
2. Description of the Related Art
Soil compacting machines are typically driven by internal combustion engines and/or electric motors. While internal combustion engines enable largely independent operation of the soil compacting device due to the storage of the fuel in a tank on the machine, through the use of electric motors stress on the environment and on an operator operating the soil compacting machine can be avoided. The supply of power to the electric motor generally takes place via an external connection to the public power supply network or, for example in the case of smaller soil compacting machines, via an electric accumulator.
With the use of electric motors, the rotational frequency of the electric motors required to produce the motor power is significantly higher than the operating frequency of the compactor, i.e. the tamping or vibration frequency. As a consequence, reduction gear mechanisms are provided between the drive motor and the tamper or vibration system, which reduce the frequency of rotation of the drive movement produced by the electric motor and increase the drive torque.
Such reduction gear mechanisms contain complex assemblies that require adequate constructive space, have a high weight, and result in high production costs. During operation, they are exposed to strong loads, have a high degree of wear, and thus result in limited reliability of the overall system.
During the driving of the soil compactors, fast-rotating electric motors consequently act on the soil contact element via step-down gear mechanisms and spring packets. Thus, as a result of the design it is not possible to infer the position of the tamper foot and its loading condition from the angle of rotation of the drive motor. Rather, the tamper frequency, an impact speed, and the temporal course of the impact process are a function of the system variables of the soil compacting device and of the condition (rigidity) of the soil being compacted.
In their conception and design, tampers are adapted to the conditions of uncompacted standard soils in such a way that the best possible compaction effect of the machine is achieved precisely when the properties of the soil agree with the soils taken into account in the dimensioning of the tamper system. When compacting soils having different properties, the tamper effect can therefore be less.